Foldable extension device



Dec. 31, 1929. KRAEMER 1,741,421

FOLDABLE EXTENSION DEVICE v Filed Jan. 16, 1929 IN V EN TOR.

BWM 44 A TTORNEYS.

Patented Dec. 31, 1929 unrrao STATES PATENT OFFICE AUGUST F. KRAEMER, F PROVIDENCE, RHODE ISLAND, ASSIGNOR TO LOUIS STERN COMPANY, OF PROVIDENCE, RHODE ISLAND, A CORPORATION OF RHODE ISLAND FOLDABLE EXTENSION DEVICE Application filed January 16, 1929. Serial No. 332,803.

This invention relates to a foldable extension device for a wrist strap; and has for its object to provide an improved means for securing the sections in folded position.

A. further object of the invention is the folding of a portion of one of the sections for engagement with fingers on another sec tion to secure the sections in folded position.

A still further object of the invention is the construction of the securing means from sheet stock by suitably bending operations to form a strong releasable clasp to secure the sections against inadvertent or accidental unfolding. I

lVith these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described, and particularly pointed out in the appended claims.

In the accompanying drawings:

Fig. 1 is a top plan view of the extension device in folded position with the strap parts attached thereto.

Fig. 2 is a perspective view of the device in partially unfolded position.

Fig. 3 is a sectional view of the device in folded position with the resilient clasp part-s in engagement.

Fig. 4 is a section on line 4-4 of Fig. 5 of the outer or cover section.

Fig. 5 is a section on line 4-4 of Fig. 5 showing the clasp in engaged position.

It is found in practice in the wearing of a wrist band with a foldable extension device interposed therein that in certain uses of the arm a strain is exerted upon the strap which tends to unclasp and unfold the same, and it is desirable that a strong yet releasable clasp may be provided which will secure these parts in folded position against such strains as are customarily exerted upon the strap when in use and yet be so constructed that it may be-formed from sheet stock and will yield to manual unclasping to permit unfolding of the device when desired; and in order to accomplish these results, I have folded inwardly portions at the end of the channel cover section and cut and folded from another end section suitable fingers for engagement therewith to secure the parts in the desired folded position; and the following is a detailed description of the present embodiment of this invention illustrating the preferred means by which'these'results are accomplished:

WVith reference to the drawings, designates one end section of the device having side walls 11 and a top outer wall 12 forming in cross section a substantially channelshaped construction. Openings 13 in the side walls are provided for suitably attaching a strap part 14 thereto by means of the usual tip 15.

The opposite end section 16 of the device is illustrated as a plate and is provided with a pair of eyes 17 for attaching the strap part 18 thereto by means of the tip 19 havingan eye 20 to align with eyes 17 and receive a pin therethrough.

The two end sections are secured together by suitable means to permit one to' be folded upon'the other, and I have here illustrated this connection as a separate plate section 21 hingedly secured at 22 to the plate section 16 and also hinged at 23 to the side walls of the section 10 by which construction the sections may be folded one upon the other, as illustrated in Fig. 3.

In order to secure the sections in this folded position, I have provided extensions on the side walls of the section 10 and folded these inwardly, as illustrated-in Fig. 2, to provide resilient portions 24 spaced from the side walls with the bight or folded portion 25 extending towards the opposite end section when in folded position. The spacing of the portions 24 from the side walls 11 permits of resiliency of action when engaged by the fingers 26 formed by suitably cutting the plate 16 and bending the cut portions at substantially right angles to the plate, which fingers are also resilient to cooperate with the inwardly folded portions 24 to frictionally retain the sections in folded position.

Fingers 26 are reversely curved as illus trated in Fig. 5, such that end portions 27 may overlie the end 28 of the inwardly fold-- ed portion 24 to more securely hold the sections in folded position but permit the same to be manually released due to the extreme resiliently between the connected parts.

It is of-course understood that the fingers 26 and the inwardly folded portions 24 are formed of stock having a sufficient hardness to provide the requisite stiffness for suitably holding the parts together.

The foregoing description is directed solely towards the construction illustrated,'but I lesire it to be understood that I reserve the privi'legeof resorting -to all the mechanical changes to which the device is susceptible, the invention being defined and limited-only by the terms of the appended claims.

I claim:

1. A .foldable extension device for a wrist strap comprising a plurality of sections hingedtogether to befolded one onanother, means for retainingsaid sections in folded position, comprising spaced inwardly folded resilient portions on one of said sections, presenting the'bight of the fold .to cooperating portions on a secondsection, and fingers on said second section forming said cooperatingportions and, resiliently contacting said folded portions in substantially parallel relationship for holding said sections in folded position.

2. A foldableextension device for a wrist strap comprising a plurality of sections hinged together to be folded one on another, one of said sections being channel shape in cross section and having side walls, a portion of said side walls being turned inwardly in parallel relation to said side walls and spaced therefrom, and fingers on another of said sections for frictional engagement between said inwardly turned portions for holding said section in folded position.

3. .A foldable-extension device fora wrist strap comprising a "plurality of sections hingedtogether'to be 'foldedone on another, oneend section being channel'shape in cross sectionand having side walls, a portion of said side walls being turned inwardly, and

spaced from the side walls in parallel relationitherewithto present resilient portions, and -fingers folded'from the stock of the opposite end section for frictional engagement between said resilient portions for holding said sections-in folded position.

4. A ifoldable extension device for awrist strap, comprising a pair of end sections, means including another section hingedly joining saidsections togetherto permitifolding one on another, means for retaining said sections in foldedposition comprising spaced portions carried by one end section, each turned'upon itself andpresenting the folded edge towards the other-end section when the device is in foldedpositiomand fingers on the other end-section to frictionally engage said foldedtportion insubstantiallvparallel relationship.

5. A foldable-exension device *for a :wrist strap, comprising a pair of end sections, means including another section hingedly joining said sections together to permit folding one on another, one end section being channel shape in cross-section and having side walls, a portion of the opposite side Walls thereof being turned inwardly in parallel relation to said side walls and spaced therefrom, the other of said end section being AUGUST F. KRAEMER. 

